1. Field of the Invention
The present invention relates to a control device, an image forming system and a computer program product.
2. Description of the Related Art
In the related art, it is known that, in an image forming device such as a printer and a copying machine, if the used amount of color material (i.e. recording material) such as a toner and an ink is excessive, for example, image quality degrades. For example, in an electrophotography image forming device, if the used amount of toner is excessive, a fixing trouble or transcription trouble (i.e. uneven color) is likely to occur.
It is known that the above problem can be solved by suppressing the total amount of color material, which is used to draw one pixel, to be equal to or less than a predetermined restriction value (i.e. total amount restriction). For example, Japanese Laid-open Patent Publication No. 2005-311558 discloses a technique of determining a restriction value based on the total sum of the density values of colors of pixels included in a restriction target area, printing conditions, the total sum of the density values of colors of pixel values included in a peripheral area, and so on.
Here, in total amount restriction in the related art, since common restriction is performed on the color material of each color (i.e. the reduction of each color material is commonly set), there is a problem that the color expressiveness degrades depending on the type of an image to be displayed (e.g. natural image).
The present invention is made in view of the above and it is an object of the present invention to provide a control device, image forming system and computer program product that can improve image quality.